[open] Config file is now named openrc

More standard conform (basically ~/.config/${APPNAME}/${APPNAME}rc). And
yes, I'm aware this happens to have the same name as Gentoo's init
system.
Use xmodmap more extensively

The Escape/CapsLock swap is done manually now, as are the ergonomic
mappings for Backspace/Delete/Enter on AltGr+j/k/l.
Furthermore, most of the xmodmap changes is put in
.config/xmodmap/xmodmaprc, in order to keep things a little more clean.
Move git configuration to ~/.config/git

Also, given that my e-mail appears in every commit I do, there's no need
to hide the git configuration out of fear of exposing that same e-mail
address.

Move .gitignore there, too (it's neatly mentioned in the config, so I
can basically put it wherever I want).